Which of the following search methods relies on a pre-defined controlled vocabulary rather than natural-language text entered by the user?

### Why this is right Subject searching uses a **controlled vocabulary**, a fixed set of approved terms used to describe items in a library database. The database assigns these terms to resources, so a search can find relevant material even when the resource uses different wording from the searcher. ### The concept In subject searching, you choose an approved subject term, often called a **subject heading**, which is a standardized label for a topic. This differs from searching with natural-language words, the ordinary words a user types, which may appear in a title or text without being assigned as a subject. Related search methods work differently: keyword searching looks for words in a record or document, phrase searching looks for an exact sequence of words, and truncation searching uses a symbol to find several word forms that share a beginning. | Method | What it searches | |---|---| | Subject searching | Approved topic labels assigned to resources | | Keyword searching | Words appearing in records or documents | | Phrase searching | An exact sequence of words | | Truncation searching | Word forms sharing a specified beginning | ### The other options - **B. Keyword searching**: searches for words in records or document text, rather than relying on approved topic labels. It is tempting because users can enter their own words. - **C. Phrase searching**: searches for an exact sequence of words, often by placing them in quotation marks. It does not depend on a controlled vocabulary. - **D. Truncation searching**: uses a symbol, commonly an asterisk, to retrieve word forms with a shared stem. It changes how word endings are matched, not which approved subjects are used. ### Terms - **Controlled vocabulary**: A fixed set of approved terms used to describe and organize resources by topic. - **Subject heading**: A standardized topic label assigned to a resource. - **Natural-language text**: Ordinary words and phrases people use when speaking or writing. - **Keyword searching**: Searching for entered words wherever they occur in a record or document. - **Phrase searching**: Searching for words in a specified, exact order. - **Truncation searching**: Searching with a symbol that stands in for the endings of words sharing a common beginning. ### Remember If the search relies on approved topic labels assigned to resources, it is subject searching; if it looks for the words you type, it is keyword searching.